Single chloride channel currents from canine tracheal epithelial cells.
Single chloride channel currents from canine tracheal epithelial cells.
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来自犬气管上皮细胞的单氯离子通道电流。
DOI：
10.1016/0005-2736(86)90328-7
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发表时间：
1986
期刊：
影响因子：
--
通讯作者：
Farley,JM
中科院分区：
文献类型：
--
作者：
Shoemaker,RL;Frizzell,RA;Dwyer,TM;Farley,JM
使用膜片钳技术来表征原代培养物中维持的犬气管上皮细胞中阴离子选择性通道的特性。在单个分离的细胞或汇合片边缘的细胞中获得了千兆欧姆密封（10-30 GΩ），并在细胞附着或从内到外、切除的贴片配置中研究了通道。用等渗 KCl 进行预处理使细胞聚集，使我们能够更好地成功获得良好的密封。基于电导、阴离子-阳离子选择性和电压依赖性动力学特性，可以在 0.15 M NaCl 的对称溶液中检测到四种阴离子通道类型；(i) 高选择性的 30–50 pS Cl− 通道，在负电位下激活，在大正电位下失活；(ii) 大约高选择性的 20 pS Cl− 通道，在正电位下激活，在负电位下失活；(iii)中等选择性 (P Cl P Na= 4) 的 250 pS 通道，不依赖于电压，以及 (iv) 大约 250 pS 通道。 10 pS Cl− 通道的特性与上述 (iii) 类似，但在大负电压下仍保持一定程度的活性。所有切除的斑块的细胞内侧均暴露于相对较高的钙浓度。用 1 mM cAMP 处理的气管细胞中通道活性增加，表明这些通道中至少有一个在由 cAMP 介导并由活性 Cl- 分泌激动剂引发的顶膜 Cl- 电导增加中发挥作用。
Patch-clamp techniques were used to characterize the properties of anion-selective channels in canine tracheal epithelial cells that had been maintained in primary culture. Gigaohm seals (10–30 GΩ) were obtained in single isolated cells or cells at the edge of a confluent sheet, and channels were studied in the cell attached or the inside-out, excised patch configuration. Pretreatment with isotonic KCl caused the cells to round-up and allowed us to have better success in obtaining good seals. Based on conductance, anion-cation selectivity and voltage-dependent kinetic properties, four anion channel types could be detected in symmetrical solutions of 0.15 M NaCl;(i) a 30–50 pS Cl− channel of high selectivity, active at negative potentials and inactivated by large positive potentials;(ii) an approx. 20 pS Cl− channel of high selectivity, active at positive potentials and inactivated at negative potentials;(iii) an approx. 250 pS channel of moderate selectivity (P Cl P Na= 4) that was not voltage-dependent, and (iv) an approx. 10 pS Cl− channel with characteristics similar to (iii) above, but remaining somewhat active at large negative voltages. All excised patches were exposed to relatively high calcium concentrations on the intracellular side. Channel activity was increased in tracheal cells treated with 1 mM cAMP, suggesting that at least one of these channels plays a role in the increase of the apical membrane Cl− conductance that is mediated by cAMP and elicited by agonists of active Cl− secretion.